O-alkyl-s-unsaturated aliphatic hydrocarbyl phosphoroamidothioates

ABSTRACT

PHOSPHOROAMIDOTHIOATES OF THE FORMULA:   R-S-P(-O-R&#39;&#39;)(=O)-NH-R&#34; WHEREIN R IS MONOVALENT UNSATURATED ALIPHATIC HYDROCARBYL RADICAL SUCH AS ALLYL OR PROPARGYL, R&#39;&#39; IS LOWER ALKYL AND R&#34; IS HYDROGEN OR LOWER ALKYL. PHOSPHOROAMIDOTHIOATES OF THIS GROUP ARE INSECTICIDAL.

United States Patent 9 3,649,723 O-ALKYL-S-UNSATURATED ALIPHATIC HYDRO- CARBYL PHOSPHOROAMIDOTHIOATES Philip S. Magee, San Rafael, Calif., assignor to Chevron Research Company, San Francisco, Calif.

N Drawing. Filed Sept. 9, 1965, Ser. No. 486,233 Int. Cl. A01n 9/36; C07f 9/24 US. Cl. 260-956 Claims ABSTRACT OF THE DISCLOSURE Phosphoroamidothioates of the formula:

1T -NHR wherein R is monovalent unsaturated aliphatic hydrocarbyl radical such as allyl or propargyl, R is lower alkyl and R" is hydrogen or lower alkyl. Phosphoroamidothioates of this group are insecticidal.

This invention relates to a unique group of phosphoroamidothioates and their use as insecticides. More particularly, it concerns O-alkyl-S-unsaturated aliphatic hydrocarbyl phosphoroamidothioates and their use as contact and systemic insecticides.

The compounds of this invention are phosphoramidothioates, wherein an unsaturated aliphatic hydrocarbyl group is bonded to the sulfur, a lower alkyl group is bonded to the oxygen which is covalently bonded to the phosphorus and the amido group is either unsubstituted or singly substituted with a lower alkyl group.

In terms of structure, these novel compounds may be represented by the following general formula:

wherein R is a monovalent unsaturated aliphatic hydrocarbyl radical, R is lower alkyl and R" is hydrogen or lower alkyl. The univalent hydrocarbyl radical, R, may contain single or plural sites of aliphatic unsaturation. The sites of unsaturation may be the same or different, that is to say, ethylenic and acetylenic sites may be present in a given radical. These sites may be located in any position within the radical. Usually there will be not more than 2 sites of unsaturation in the radical, and more usually there will be only a single site. The preferred compounds are those wherein R" is hydrogen and R is an aliphatic hydrocarbyl group having from 3 to 6 carbon atoms which has a single terminal site of aliphatic unsaturation. Particularly preferred compounds are those wherein R is propargyl. Lower alkyl as used herein includes alkyl groups having from 1 to 6 carbon atoms.

Examples of compounds which fall within the above formula are:

O-methyl-S-allyl phosphoroamidothioate,

O-ethyl-S-( l-propenyl) phosphoroamidothioate, O-propyl-S-allyl methylphosphoroamidothioate, O-butyl-S 3-butenyl) phosphoro amidothio ate, O-hexyl-S-(Z-butenyl) ethylphosphoroamidothioate, O-methyl-S-( l-butenyl) phosphoroamidothioate,

O- i-propyl) -S- 2-pentenyl) phosphoroamidothioate, O-ethyl-S-( i-pentenyl) propylphosphoroamidothioate,

O-amyl-S-( l-hexenyl) phosphoroamidothioate, O-methyl-S- S-hexenyl) methylphosphoroamidothioate, O-ethyl-S- 3 -hexenyl) phosphoroamidothioate, O-methyl-S- l-propynyl) phosphoroamidothioate, O-butyl-S-( l-propynyl) ethylphosphoroamidothioate, O-ethyl-S- Z-butynyl) phosphoroamidothioate, O-methyl-S- 3-butynyl) butylphosphoro amidothioate, O-hexyl-S-( l-butynyl) phosphoroamidothioate, O-(s-butyl)-S-(4-pentynyl) i-propyl phosphoroamidothioate, O-ethyl-S- 3-pentynyl) phosphoroamidothioate, O-rnethyl-S- S-hexynyl) phosphoroamidothioate, O-methyl-S- 1,3-butadienyl) phosphoroamidothioate, O-ethyl-S-( 1-buten-3-ynyl) phosphoroamidothioate, O-ethyl-S-(2-penten-4-ynyl) methylphosphoroamidothioate, O-methyl-S-( 1,3,5-hexatrienyl) phosphoroamidothioate, O-ethyl-S-( 1,3-butadiynyl) phosphoroamidothioate, 'O-methyl-S-( 1,5-hexadiynyl) phosphoroamidothioate, O-ethyl-S- 2,4-hexadiynyl) phosphoroamidothioate, O-methyl-S-(1,5-hexadien-3-ynl) phosphoroamidothioate, etc.

Examples of the particularly preferred compounds of this invention are: O-methyl-S-propargyl phosphoroamidothioate, O-ethyLS-propargyl phosphoroamidothioate, O- butyl S propargyl phosphoroamidothioate, O-hexyl-S- propargyl phosphoroamidothioate, O-methyl-S-propargyl methylphosphoroamidothioate, O propyl S propargyl ethylphosphoroamidothioate, O i propyl 'S-propargyl butylphosphoroamidothioate, etc.

The phosphoroamidothioates of this invention may be prepared by reacting an 0,0-dialkyl chlorophosphorothionate with ammonia or a primary alkyl amine and then heating the reaction product in the presence of an unsaturated acyclic hydrocarbon halide having from 3 to 6 carbon atoms and wherein the halogen is of atomic number 17 to 53. The degree of reactivity of the bromides, and in some cases the iodides, of the unsaturated aliphatic hydrocarbons make these species particularly suitable for use in this reaction.

The relative amounts of reactants employed must at least approximate stoichiometric proportions. Usually excess halide will be used. In terms of ratios, the mol ratio of halide to aminated phosphorothioate will be from about 1.0 to 10.

In the amination of the chlorophosphorothionate it is preferable to use an inert diluent such as an aromatic or paraffinic solvent. The ammonia and gaseous alkyl amines may be passed as such through the phosphorothionate solution. The liquid primary alkyl amines may be added directly to the solution. The inert diluent will normally be removed prior to the addition of the halide of the unsaturated aliphatic hydrocarbon. Removal of the diluent may be conveniently accomplished by stripping.

Heating of the stripped reaction product in the presence of halide will usually take place at temperatures between about 20 to C. For convenience, reflux temperatures may be used in this step. Excess halide may be removed from the final product by known methods such as distillation. Further purification of the product may be achieved by dissolving it in an inert solvent, removing insoluble by-products and stripping the solvent under subatmospheric pressure.

The following examples illustrate the compounds of this invention and their method of preparation. These examples are offered by way of illustration and are in nowise limiting on the invention described herein.

EXAMPLE I Into a flask were placed 10 ml. of 0,0-dimethy1 phosphoroamidothioate and 20 ml. of propargyl bromide. This mixture was refluxed for 6.5 hours, after which the contents were stripped at 70 C., 0.1 mm. Hg. An oil residue of O-methyl-S-propargyl phosphoroamidothioate was left, The structure of this product was verified by infrared and nuclear magnetic resonance analyses. Its analysis for percent P and S were, respectively: Ca1c., 18.78; found, 17.75; calc. 19.41; found, 2108.

EXAMPLE II By the manner described in Example I, using O*,O-diethyl phosphoroamidothioate as a starting material, 10.6 gms. of O-ethyl-S-propargyl phosphoroamidothioate were prepared. This compound was observed as a brown liquid having the following analysis: Percent Ncalc.: 7.82, found, 7.08; percent Pcalc.'. 17.28; found: 16.42.

EXAMPLE III A reaction vessel was charged with 8 gl'IlS. of 0,0-diethyl phosphoroamidothioate and 25 mls. allyl bromide. This mixture was refluxed for 11 hours after which it was stripped at 60 C., 0.1 mm. Hg, leaving a brown oil residue which solidified on standing. The solid was broken up, slurried with hexane, filtered and washed with hexane to provide 7.9 gms. of O-ethyl-S-allyl phosphoroamidothioate. This compound was observed as a tan solid having a melting point of 32-34 C. Its analysis was: percent N--calc.: 7.74, found: 7.04; percent P-calc.: 17.10, found: 17.95.

EXAMPLE IV A reaction vessel was charged with 10 gms. of 0,0- diethyl methylphosphoroamidothioate and 20 mls. propargyl bromide. This mixture was refluxed for 11 hours, after which it was filtered and stripped to 50 C., 0.05 mm. Hg. A 10.9 gm. portion of O-ethyl-S-propargyl methylphosphoroamidothioate was thus recovered as a brown oil. The analysis of this compound was: percent Ncalc.: 7.26; found: 6.48; percent Pcalc.: 16.03; found: 14.95.

The phosphoroamidothioates described in Examples I through IV were evaluated as contact insecticides against aphids, flies, mites and other insects.

The method used in the tests concerning the aphids and mites is called the Leaf Dip Method. In this method of 1% acetone solution of the compound to be tested is diluted with water to the desired concentration. Three replicate Fordhook lima bean leaves in the trifoliate stage infested with mites and 3 replicate National Pickling cucumber leaves infested with at least 20 individual aphids are used. l-mch leaf is dipped into the dilution of the compound, excess water is drained off and the leaf is placed in a petri dish having a piece of damp filter paper covering its bottom. The dish is allowed to dry, it is redampened with water, capped and incubated for 24 hours at 75 F. After this period, the mortality is observed and percent control is determined as compared to a standard.

The method used in the tests on flies and milkweed bug is conducted as follows: A 1% acetone solution of the toxicant is diluted further with acetone to the desired concentration and placed in a 1 ml. syringe set to displace doses. A random mixture of male and female houseflies are anesthetized with CO and 3 replicates of 20 flies each are sorted out and placed on squares of corrugated cardboard. To each of these flies are applied directly two 0.5x doses of the acetone solution from the syringe. Each replicate is then placed in a covered onehalf pint recovery cage along with a piece of watersoaked cotton wick. The cages are placed in a recovery chamber at 75 F. and observed for mortality after 24 hours. Control is reported as the percentage of the flies 4 dead after this period. The results of this contact insecticidal testing are reported in Table I.

phoramidothioate.

NOTE: MMites (Tenan chm ielarius L.)

F-Flies (Musca dom-estica L.) A-Aphids (Aphis gossypii Glover) M.B.-Milkweed bug (Oncopcltus facz'atus, Dal.)

The new phosphoroamidothioates of this invention Were also tested for effectiveness as systemic insecticides. For this testing a soil drench method was used which employs the two-spotted mite (Tetranychus telarius L.) as the organism with 3 replica 10-14 day old Fordhook lima bean plants as the hosts. A 1% solution of the phosphoroamidothioate in acetone containing 12 drops of a liquid premixed emulsifier is prepared. This solution is diluted with water to the desired concentration and 25 ml. of it is applied to the soil around each plant. After 48 hours the plants are infested with mites by placing the plants in the mitehouse and covering them with infested leaves from the stock colony. After 48 hours the plants are inspected for mite mortality. This mortality is compared with a standard and the percent control is determined. Table 11 reports the results of these tests.

0 ethyl S propargyl methylphosphoroamidothioate 92/100 In controlling and killing insects these unique phosphoroamidothioates may be applied either directly to the organism or to any environmental area which is a host to insects or susceptible to insect attack. For example, insecticidal formulations containing toxic amounts of these new phosphoroamidothioates may b sprayed directly on the insects. For systemic application, these formulations may be sprayed or otherwise applied to the plant or other host, its seed or its immediate environment, such as the soil surrounding it.

Aside from the specific toxic formulation of these compounds represented in the foregoing tests, they may be made up in a variety of other liquid and solid compositions. Solid formulations will comprise a toxic amount of phosphoroamidothioate with a suitable, biologically inert solid carrier such as powder, granules or dust.

The insecticidal compounds of this invention are, in general, water miscible and to some extent miscible in hydrocarbon solvents such as alkanes and aromatic solvents. As the size of the radical R in the above structural representation increases, the solubility in hydrocarbon solvents increases. Consequently, the solvent chosen for liquid formulation will depend upon the particular compound being formulated. Also, dispensing and Wetting agents may be used in formulating these compounds.

Further, these compounds may not only be applied alone or in mixtures with other compounds of the disclosed class, but they may also be used in combination with other active toxicants in the making of agriculturally useful compositions for control of plant infesting insects.

As will be evident to those skilled in the art, various modifications on this invention can be made or followed, in the light of the foregoing disclosure and discussion, without departing from the spirit or scope of the disclosure or from the scope of the following claims.

I claim:

1. A compound having the formula:

l NHR wherein R is a monovalent aliphatic hydrocarbyl group 6 having from 3 to 6 carbon atoms and a single terminal site of aliphatic unsaturation, R is a lower alkyl group and R" is hydrogen or a lower alkyl group.

4. A compound according to claim 3, wherein R is hydrogen.

5. A compound according to claim 3, wherein R is a propargyl group.

6. O-methyl-S-propargyl phosphoroamidothioate. 7. O-ethyl-S-proparyl phosphoroamidothioate. 8. O-ethyl-S-propargyl methylphosphoroamidothioate. 9. O-ethyl-S-allyl phosphoroamidothioate. 10. Compound of the formula RS (T) PNHR wherein R is propenyl or propynyl, R is methyl or ethyl and R" is hydrogen or methyl.

No references cited.

ALEX MAZEL, Primary Examiner A. H. SUTTO, Assistant Examiner US. Cl. X.R. 

